Solid Waste Collection and Transport

Solid Waste Collection and Transport • On-site Handling, On-site Storage : Curb Collection,Direct haul, transfer station • Collection services: types and methods • Vehicle and labor requirements • Types of Collection systems (hauled container system, stationary container system)

ON-SITE HANDLING: - Activities associated with the handling of SW until they are placed in the containers used for storage before collection ON-SITE STORAGE: Factors considered: • Types of containers used • Container Locations • Public health • Aesthetics • Methods of Collection

Factors considered: i) Types of Containers: • Depend on: • characteristics of SW collected • E.g. Large storage containers (Domestic SW: flats/apartment) • Containers at curbs • Large containers on a roller (Commercial/Industrial) • Collection frequency • Space available for the placement of containers( Refer to Table 11-4) - Residential; refuse bags (7 -10 litres) - Rubbish bins - 20 -30 litres - Large mechanical containers - more commonly used to cut costs (reduce labor, time , & collection costs) - must be standardized to suit collection equipment.

ii) Container Locations: - side/rear of house - alleys - special enclosures (apartment/condos) • Basement (apts. in foreign countries)/ newer complexes iii) Public Health: • relates to on-time collection to avoid the spread of diseases by vectors, etc. iv) Aesthetics: - must be pleasing to the eye (containers must be clean, shielded from public’s view).

v) Collection of SW - 60-80 percent of total SWM costs. - Malaysia (other developing nations) - labor and capital intensive. - Major problems: • Poor building layouts - e.g. squatters • Road congestion - time cost, leachate, transport costs. • Physical infrastructure • Old containers used (leaky/ damaged) • Absence of systematic methods (especially at apartments, markets with large wst. volume).

Collection of SW(cont.) • Collections were made by: • Municipal/ District Council • Private firm under contract to municipal • Private firm contract with private residents • After Privatization (1998) - A Consortium of mngt. companies were given the responsibility. • (e.g. SWM (The Southern Waste Management - handles southern region) took over the mngt. from MBJB/MPJBT; Alam Flora (Central Region).

TYPES OF COLLECTION: • Municipal Collection Services: a. Residential: • Curb (Kerb-side), alley, and backyard collection (100-120 litres) • Quickest/ economical • Crew: 1 driver + 1 or 2 collectors • No need to enter property • Most common in Malaysia.

TYPES OF COLLECTION (Cont.) ii. Set-out, set back: - Collectors have to enter property - Set out crew carries full containers from resident storage location to curb/ alley before collection vehicle arrives. - Collection crew load their refuse into vehicle • Set-back crew return the container to storage area. • House-to-house collection where refuse bags used in 20-30 liter bins.

High-rise apartment or flats, specially designed chutes or a communal storage or roll-on-roll-offs (RORO’s). • Future trend: mechanically-equipped trucks. b) Commercial-Industrial Collection Services ( > 12 m3 ) i. Large movable and stationary containers ii. Large stationary compactors (to form bales)

Collection Frequency: - residential areas : everyday/ once in 2 days - communal/ commercial : daily - food waste - max. period should not exceed : • the normal time for the accumulation of waste to fill a container • the time for fresh garbage to putrefy and emit fouls odor • the length of fly-breeding cycle ( < 7 days).

TYPES OF COLLECTION SYSTEMS: 1. Hauled Container System (HCS) 2. Stationary Container System (SCS) 1. HCS: - Container is hauled to disposal sites, emptied, and returned to original location or some other location - Suitable for areas w/ higher wst. generation - Types: • Hoist truck : 2 - 10 m3 • Tilt frame container: 10 - 40 m3 - • Trash trailer - for heavy, bulky rubbish (construction, commercial, usually open top container); • 2 crew per vehicle.

TYPES OF COLLECTION SYSTEMS (Cont.) 2. SCS: - the container used to store waste remain at the point of generation; except when moved to curb or other location to be emptied. • Types include: • Mechanically-loaded system • Manually-loaded collection vehicle(more common). - Used for residential/commercial sites. • Vehicle w/ internal compaction mechanism or un-compacted (open top lorry - side loaded. • Refer to Figure: 11-10 (handout).

PRIVATIZATION OF SWM: • Specific tasks of the company included the following: • To take over the collection and disposal of solid waste and cleaning activities of MPJBT • To employ the staff of MPJBT involved in both activities • To take over property involved with both activities • To take over contracts currently held by the Council.

SWM - strategies to improve : • increasing number of vehicles and staff • rearranging work areas to increase productivity • opening up new tenders for newer development areas • repairing vehicles • upgrading drainage-cleaning performance, collection of illegal dumping sites, and opening up new cells at Ulu Tiram landfill site (Southern Waste Management, 1998).

COST ACCOUNTING FOR SW COLLECTION SYSTEM: - Part of management control - Accounting concepts must be utilized to the maximum. - Referred to as an “Enterprise Fund Accounting”.

Costs in SW Collection Systems: • Capital Costs (i.e. depreciation (susut nilai) costs for vehicles, garages, administrative services). • Interest costs of debt (to acquire /construct facilities/equip.) • Costs (i.e., labor, parts, oil, tires) of repairing and maintaining facil./equip.). • Employee benefits (pension, etc.). • Cost of temporary employees (short-term needs).

Costs in SW Collection Systems(Cont.): • Overhead costs (executives, supporting staff). • Costs associated with budgeting, accounting, and report activities. • Costs associated with billing and collecting user charges. • Liability and damage claims. • Insurance premiums (personnel, facilities, and equipments).

TRANSPORT COSTS: • estimates of the costs per km and per hour to move the waste after collection from the end of collection route to the various facility locations in the study. • Unit transport cost (RM/km) for various types of vehicles : • Collection vehicle • Transfer vehicles • Residue and/or ash vehicles • Labor costs (driver + crew in RM/hr unit cost) only for (i) and (iii). • For (ii) - labor costs should be included as part of the annual labor cost of the transfer station.

Factors Affecting SW Collection Productivity: a. Service Level Related: • collection point, frequency, waste material b. Route related: • Containers, Distance, constraints, topography, delays, road conditions c. Collection Methodology Related/Climate Related: • Crew size, collection procedures, wind, rain.

ANALYSIS OF COLLECTION SYSTEMS - Must be optimized to save collection time and costs. - Important to determine vehicle and labor requirements - Activities involved 4 units: pick-up, haul, at-site and off-route.

Waste Collection Models Determination of Vehicle and Labor Requirements.

LAY-OUT OF ROUTES: 4-Step Process 1. Prepare location maps: - with pick-up point locations - number of containers - collection frequency - estimated quantities (in the case of SCS with self-loading compactors).

2. Data summaries: - Estimate of wst. each day (from pick-up locations) - ( for SCS - number of locations for each pick-up cycle). 3. Lay preliminary collection routes (from different stations). - Route should connect all pick-up locations + last location be nearest to disposal site). 4. Develop balanced route - determine haul distance for each route - Determine labor requirements per day, check against available work times per day - draw master map.

SOLID WASTE COLLECTION: Selecting Collection Equipment: - Changing needs and advances in technology - Trends - increase use of computer-aided equipment and electronic control (e.g. on-board computers for monitoring truck performance and collection performance). - Most prevalent: compactor trucks (equipped with hydraulically powered rams that can compact wastes to increase payload). - Open and close non-compacting trucks: o Inexpensive to purchase or maintain o Inefficient for most collection application (small amt. of waste, have to lift high to dump into the truck) o Suitable for yard, bulky wastes, and recyclable materials, for small communities and rural areas.

Factors to consider in selection of vehicle: • Waste quantities • Truck body or container capacity • Regulations regarding truck size and weight, • To maximize the amount of wastes that can be collected while remaining within legal weights for the overall vehicle. • Consult with collection crew and drivers. • Loading location/ Location of container - determine the type of vehicles to be used: Front-loading; Side-loading or rear-loading compactor truck. • Physical characteristics of the collection routes/ road width - e.g. wide street - use side-loading automatic collection system; for narrow urban streets - use rear loaders.

Factors to consider in selection of vehicle(Cont.): • Residential, commercial or industrial: HCS for large buildings (e.g. apt., industries,etc.) • Safety and comfort - to minimize danger to crews. • Truck turning radius - be as short as possible. • Water tightness - to prevent leakages. • Speed - wide range of speed.

TRANSFER OF MUNICIPAL WASTE: - More common as the distance of landfill sites becomes greater - Most common in larger metropolitan areas. - Variance in types, size, and degree of sophistication - E.g. open-air stations or enclosed in a building (newer stations).

Advantages of Transfer stations: - better haul roads for collection vehicles (usually paved - reducing damages to trucks and delay). - greater traffic control (avoid traffic jams/congestion or litter + safety to children). - fewer truck on the sanitary landfill haul routes( reduction ratio of from 3 (trucks) :1 (transfer haul) or 5:1). - improved landfill operating efficiency (fewer trucks mean better traffic control). - Lower overall haul cost (reduction in no. of drivers/crew).

Criteria for Transfer Location: -Near the collection area served (to minimize collection crew time for haul to the transfer station). - Accessible to major haul routes (public acceptance and economics - lower transfer haul cost)). • Adequate land area to provide isolation (to handle traffic flow). • Suitable Zoning (commercial or industrial) - Served by utilities (water, sanitary sewer, storm drainage, electricity) ( Size vs. station capacity)

Station Concepts • Pit • Direct Dump • Compaction • Pit: • Collection vehicles unloaded wastes into a large pit. • Wastes are then pushed to an open-top transfer trailer by a tractor. • The pit - as storage during peak periods. • Compaction of bulk items made by the tractor in the pit.

Direct Dump: • collection vehicles dump directly into open-top transfer trailer • Large hoppers direct the waste into the transfer trailers. • Very large transfer trailers are used (due to minimal compaction). • Efficient - no intermediate handling required (direct from vehicle to transfer trailer).

3. Compaction: i) Hopper type compaction station : waste drop by gravity into a compactor - packs the waste into the trailers. ii) Push pit compactor station: a large hydraulically operated blade moves the waste to the stationary packer - then packs the waste into the trailers.

Advantages & Disadvantages of Design Alternatives:

PROCESS OPTIONS AT TRANSFER STATIONS: - To prepare waste for transfer haul and subsequent disposal 1. Baling: • - practiced in the US since 1960’s • - reduces haul cost • - a more controlled operation at the landfill • - require lower cover material • - density 1500-2000 lb/yd3 • - may have wire ties or may not be tied. - Requires little or no separation of wastes.

2. Shredding: - Shredders are used. - Handles bulky wastes (furniture, tree limbs, etc.) - Transport - use enclosed transfer trailers. - Wastes have good compaction characteristics - requires small trailers.

Solid Waste Collection and Transport